Search

This study was designed to evaluate the effects of dietary supplemental DL-methionine (MET) on live performance and meat yield for broilers raised to a common weight. A total of 1552 one-day old Ross 708, sexed broilers were randomly distributed to 32 pens resulting in eight treatments (TRT) of four replicates with 44 male or 53 female/pen. A randomized complete block with a 2 × 4 (sex × 4 MET levels 0, 0.5, 1, and 2 g/kg) factorial arrangement of TRT was used. A common weight of 2400 g was approached by day 46 (1 and 2 g MET/kg feed) and day 48 (0 and 0.5 g MET/kg feed). Supplementation of MET at 1, and 2 g/kg had a lower (p &lt, 0.01) feed conversion ratio (FCR) at day 46/48 than broilers fed 0.5 g MET/kg. Broilers without supplemental MET had the worst (p &lt, 0.01) feed conversion and average daily gain (ADG) at day 46/48. Birds fed 0 g MET/kg of feed had lower (p &lt, 0.05) whole eviscerated carcass without giblets (WOG), yield than birds fed 2 g MET/kg of feed. Additionally, birds fed 0 g MET/kg of feed had lower (p &lt, 0.05) breast fillet and tender percent yields than birds fed supplemental MET. Elimination of MET from organic broiler diets resulted in reduced ADG, breast fillet yield and feed efficiency of meat yield of broilers raised to day 46/48. Reduction in MET supplementation below current levels reduced the efficiency of meat production of organic broilers raised to day 46/48.

The effect of high-temperature and mild-pressure (HTMP) pretreatment on the enzymatic hydrolysis of phosvitin and the structural characteristics of the phosphopeptides produced were analyzed using tandem mass spectrometry. The HTMP pretreatment hydrolyzed phosvitin at random sites and helped the subsequent enzyme hydrolysis of the peptides produced. With the HTMP pretreatment alone, 154 peptides were produced, while the use of trypsin, Protex 6L, and Multifect 14L in combination with the pretreatment produced 252, 280, and 164 peptides, respectively. The use of two enzyme combinations (trypsin + Protex 6L and trypsin + Multifect 14L) helped the hydrolysis further. The number of phosphopeptides produced increased when the modifications within the same amino acid sequences were considered. This study indicated that HTMP pretreatment was a breakthrough method to improve the enzymatic hydrolysis of phosvitin that enabled an easy production of phosvitin phosphopeptides for their subsequent functional characterizations.

High environmental temperature due to climate change can accelerate oxidation of feed during storage and preparation. Oxidized feed can cause elevated oxidative stress in live birds, resulting in decreased productivity and meat quality of broilers. The study was aimed to determine effects of feed containing oxidized oil on growth performance, plasma oxidative stress, and breast meat quality of broilers. Male broilers (192; Cobb500) at 21 days old were randomly allotted to 32 pens (8 pens/treatment) and raised for 21 days. The birds were fed feed containing fresh (Control) or oxidized corn oil (5%, Peroxide Value:140) with or without vitamin E (500 IU/kg feed) supplementation. Growth performance, oxidative stress markers in plasma collected at Day 42, and quality parameters of breast meat harvested at Day 43 were determined. Data were analyzed using proc glm and means were compared using Tukey’s studentized range (HSD) test. Oxidized feed and/or vitamin E supplementation did not affect growth performance and plasma DNA and protein oxidation. Oxidized feed significantly increased lipid oxidation and reduced total antioxidant capacity in plasma (P < 0.05) and, interestingly, dietary vitamin E made them worse (P < 0.05), indicating that oxidized lipids in feed can induce oxidative stress in live birds and vitamin E may act as a pro-oxidant in highly oxidized conditions. Although they did not affect sensory and functional properties of chicken breast meat, oxidized feed significantly increased lipid oxidation in cooked meat (P < 0.05) but dietary vitamin E considerably inhibited its development (P < 0.05), indicating that oxidized oil and vitamin E in feed can be accumulated in muscle and act as a pro- and anti-oxidants in meat, respectively. The results suggested that oxidized oil in feed can increase oxidative stress in live birds and susceptibility of breast meat to lipid oxidation, and dietary vitamin E can improve its oxidative stability.

Woody Breast (WB) defines a quality issue resulting from a muscle abnormality in chicken meat, which makes the breast meat more rigid and sometimes pale in color with inferior texture. The frequency of this defect in Europe is over 30% and some have argued that similar levels may exist in the United States. Given that chicken with WB are of poor economic value and are discriminated by the consumers, producers face significant economic hardship under the current production paradigm. One of the problems in identifying the biological mechanism responsible for WB is that the occurrence and severity of WB can be only identified after harvest. This study is to investigate the physical characteristics of WB and normal breast (NB) in live chicken using a non-invasive, digital palpation device named as “MyotonPRO®”. This technology provides the measurements of superficial muscles regarding dynamic stiffness (100–1500 N/m; DS), elasticity (0.3–2.5), mechanical stress relaxation time (5–40 ms; MSRT) and ratio of deformation and relaxation time (0.3–2.5; RDRT). One hundred breast meat samples were used in this analysis (WB: 50; NB: 50), which were obtained from a local processing plant one day after harvest and sorted based on WB scoring with the naked eye (0, 1 for NB; 2, 3 for WB). One way ANOVA was used to analyze the data as a statistical model. The least squares means of the following variables were significantly different between WB and NB (P < 0.01): DS (603.4 vs 565.8; N/m), and elasticity (1.40 vs 1.55). However, MSRT and RDRT were not significantly different (P > 0.05). These results collectively show that the non-invasive measurements of WB differ from NB. The degree of muscle hardness in WB can be considered as a trait to be selected, and utilized for the genetic/genomic selection program collecting the measurements before harvest.

The objective of this study was to identify metabolites that could be associated with oxidative stability of aged bovine muscles. Three muscles (longissimus lumbrum (LL), semimembranosus (SM), and psoas major (PM)) from seven beef carcasses at 1 day postmortem were divided into three sections and assigned to three aging periods (9, 16, and 23 days). Although an increase in discoloration was found in all muscles with aging, LL was the most color/lipid oxidative stable, followed by SM and PM (P0.05). Lower myoglobin and nonheme iron contents were observed in LL compared to those in SM and PM (P0.05). The HPLC-ESI-MS-based metabolomics analysis identified metabolites that were significantly responsive to aging and/or muscle type, such as acyl carnitines, free amino acids, nucleotides, nucleosides, and glucuronides. The results from the current study suggest that color and oxidative stability could be associated with aging but are also muscle-specific. Further studies determining the exact role of the identified metabolites in the color and oxidative stability of beef muscles are warranted.

Tissue culture and mycorrhiza applications can provide disease-free seedlings and enhanced nutrient absorption, respectively, for organic farming. Ginger (Zingiber officinale Roscoe) is rich in phytochemicals and has various health-protective potentials. This study was aimed at determining effects of tissue culture and mycorrhiza applications alone or in combinations in organic farming on phytochemical contents (total phenolics and flavonoids [TP and TF, respectively], gingerol and shogaol homologues, phenolic acids, and carotenoids) and antioxidant capacities (DPPH [2,2-diphenyl-1-picrylhydrazyl] radical scavenging, oxygen radical absorbance (ORAC), and iron-chelating capacities [ICC]) in solvent-extractable (Free) and cell-wall-matrix-bound (Bound) fractions of ginger rhizome and Free fraction of the leaves in comparison with non-organics. Concentrations of the phytochemicals and antioxidant capacities, except for carotenoids and ICC, were significantly higher in organic ginger rhizomes and leaves than in non-organics regardless of the fractions and treatments (P < 0.05). Mycorrhiza application in organic farming significantly increased levels of TP, TF, gingerols, and ORAC in the Free fraction of the rhizome (P < 0.05). Furthermore, the combined application of tissue culture and mycorrhiza significantly increased concentrations of TF and gingerols and ORAC in the Free fraction of the rhizome (P < 0.05), suggesting their synergistic effects. Considerable amounts of phenolics were found in the Bound fractions of the rhizomes. Six-gingerol, ferulic acid, and lutein were predominant ones among gingerols, phenolic acids, and carotenoids, respectively, in ginger rhizomes. The results suggest that organic farming with mycorrhiza and tissue culture applications can increase concentrations of phytochemicals and antioxidant capacities in ginger rhizomes and leaves and therefore improve their health-protective potentials.

Environmental temperature has increased due to climate change, which affected broiler productivity and meat quality. Early heat conditioning (EHC) is a technique utilizing chick’s perinatal epigenetic temperature adaptation ability to improve heat tolerance of broilers. This study was aimed to determine mitigating effects of EHC against chronic (C-HS) and acute heat stress (A-HS) during the finishing period on growth performance, oxidative stress in blood and breast meat quality of broilers. One hundred eighty 1-day-old Cobb broiler chicks in 30 pens were randomly allotted to 5 groups and raised for 42 days; Two groups at 3d were exposed to EHC at 36 °C for 12h, then subjected to C-HS (12h-cyclic temperature control at 34/27 °C for the last one week) and A-HS (at 36 °C for 2h at Day 41), respectively. Two no-EHC groups were exposed to both heat challenges as negative controls, respectively. Control were without EHC and HS. Growth performance, plasma oxidative stress markers, and quality parameters of breast meat harvested at Day 43 were determined. Data were analyzed using proc mixed or glm and least-square means were compared using PDIFF. The effects of both HS against growth performance were significant but mitigated by EHC (p

The impacts of parboiling and wet-cooking, alone and in combination, on the concentrations of lipophilic antioxidants (vitamin E and γ-oryzanol), soluble (including proanthocyanidins and anthocyanins) and cell wall-bound phenolics, and antioxidant capacities in whole grain rice from six cultivars having different bran colours were investigated. Parboiling rough and brown rice increased the concentrations of lipophilic antioxidants in whole grain rice but decreased the concentrations of total phenolics and antioxidant capacities found in the soluble fraction. After hydrothermal processing of purple bran rice, the retention of extractable anthocyanins was low, but was high for simple phenolics. For proanthocyanidins found in red bran rice, the extractable oligomers with a degree of polymerization (DP) less than 4, increased up to 6-fold; while for oligomers with DP⩾4 and polymers, there was a significant decrease that was positively correlated with the DP and the temperature of the processing methods. The presence of hulls helped to retain water-soluble antioxidants during parboiling.

Thirty New Zealand White rabbits were fed diets containing 0 (control), 1, 2, 4, or 8 g cholesterol/kg diet for 12 weeks to determine the cholesterol dosageresponse of plasma cholesterol and triglycerides, and the development of atherosclerosis. The concentration of plasma cholesterol increased proportionally with the dietary cholesterol dosage during the first 4 weeks, then remained constant until the 12th week. The plasma triglycerides and TBARS concentrations gradually increased with feeding time when rabbits were fed 2 g dosages. Aortas from rabbits fed a 2 g dosage developed moderate to severe multifocal or diffusive atherosclerotic lesions. Aortas from rabbits fed 4 and 8 g dosages were diffusely affected with massive atherosclerotic lesions, and had severe calcification and Alcian blue-positive foci throughout the media of the aorta. These results indicate that at least 2 g of cholesterol/kg in the diet is needed to generate atherosclerotic lesions in rabbit aortas.

Two studies were conducted to determine the effects of dietary cholesterol (CHO) and cholesterol oxides (COPs) on the development of atherosclerosis and the changes in fatty acid and blood characteristics in rabbits. In the first study, forty male New Zealand white rabbits were divided into 5 groups and fed commercial rabbit chow with no added CHO or COPs, 1 g CHO, 0.9 g CHO + 0.1 g COPs, 0.8 g CHO + 0.2 g COPs, or 0.5 g CHO + 0.5 g COPs per kg diet. In the second study, 24 male New Zealand White rabbits were divided into 3 groups and fed a diet containing 2 g CHO, 1.6 g CHO + 0.4 g COPs, or 1.2 g CHO + 0.8 g COPs per kg diet. All diets induced atherosclerotic lesions in the rabbits’ ascending thoracic aorta. The serum CHO and triglyceride levels (p &lt, 0.05) increased significantly with the increased levels of CHO in the diets. Dietary CHO or COPs did not influence high-density lipoprotein CHO levels. The ratio of saturated fatty acid to unsaturated fatty acid increased as the level of dietary CHO and COPs increased.

Effects of dietary cholesterol [0 (control), 1, 2, 4, or 8 g cholesterol/kg diet for 12 weeks] on lipid contents and fatty acid compositions in red blood cell (RBC) membranes and plasma of rabbits and pathological changes and lipid oxidation in their livers were determined. Contents of total lipid and unsaturated fatty acids in RBC membrane and plasma of rabbits fed ≥4 and ≥2 g dosages, respectively, were significantly higher (p 2 times higher (p

To study the polyphenols in whole grain rice varying in bran colour, the total phenolics, flavonoids and antioxidant capacities of the solvent-extractable (Free) and cell-wall bound (Bound) fractions and the profiles of proanthocyanidins and anthocyanins were determined. Red and purple bran rices had significantly higher total (sum of Free- and Bound-) phenolic (PC) and flavonoid (FC) concentrations and antioxidant capacities than light-coloured bran rice or other cereals ( P P 10 mers), respectively. Cyanidin-3-glucoside was the predominant anthocyanin and peonidin-3-glucoside was the second highest; the profiles varied between purple bran cultivars. Whole grain rice differing in bran colour contained unique polyphenol subgroups, which have been proposed to positively impact human health.

The antioxidant effects of meat fractions from chicken breast and beef loin were compared. Five meat fractions – homogenate (H), precipitate (P), supernatant (S), high-molecular-weight (HMW) and low-molecular-weight (LMW) fractions – were prepared from chicken breast or beef loin. Each of the fractions were added to a phospholipid liposome model system containing catalysts (metmyoglobin, ferrous and ferric ion) or iron chelating agents to determine the effects of each fraction on the development of lipid oxidation during incubation at 37 °C for 120 min. All fractions from chicken breast showed stronger antioxidant effects against iron-catalyzed lipid oxidation than those from beef loin. Iron chelating capacity of water-soluble LMW and water-insoluble (P) fractions from both meats were responsible for their high antioxidant capacities. High concentration of myoglobin, which served as a source of various catalysts, was partially responsible for the high susceptibility of beef loin to lipid oxidation. Storage-stable ferric ion reducing capacity (FRC) was detected in all fractions from both meats, and was a rate-limiting factor for lipid oxidation in the presence of free ionic iron. Higher antioxidant capacity and lower myoglobin content in chicken breast were primarily responsible for its higher oxidative stability than beef loin. DTPA-unchelatable compounds, such as ferrylmyoglobin and/or hematin were the major catalysts for lipid oxidation in beef loin, but free ionic iron and storage-stable FRC also played important roles during prolonged storage.

The catalytic mechanism of metmyoglobin (metMb) on the development of lipid oxidation in a phospholipid liposome model system was studied. Liposome model system was prepared with metMb solutions (2.0, 1.0, 0.5, and 0.25 mg metMb/mL) containing none, diethylenetriamine pentaacetic acid (DTPA), desferrioxamine (DFO), or ferric chloride and lipid oxidation was determined at 0, 15, 30, 60, and 90 min of incubation at 37 °C. Metmyoglobin catalysed lipid oxidation in the liposome system, but the rate of lipid oxidation decreased as the concentration of metMb increased. The amount of free ionic iron in the liposome solution increased as the concentration of metMb increased, but the rate of metMb degradation was increased as the concentration of metMb decreased. The released free ionic iron was not involved in the lipid oxidation of model system because ferric iron has no catalytic effect without reducing agents. Both DFO and DTPA showed antioxidant effects, but DFO was more efficient than DTPA because of its multifunctional antioxidant ability as an iron and haematin chelator and an electron donor. The antioxidant activity of DTPA in liposome solution containing 0.25 mg metMb/mL was two times greater than that with 2 mg metMb/mL due to the increased prooxidant activity of DTPA-chelatable compounds. It was concluded that ferrylmyoglobin and DTPA-chelatable haematin generated from the interaction of metMb and LOOH, rather than free ionic iron, were the major catalysts in metMb-induced lipid oxidation in phospholipid liposome model system.

Purple rice bran contains high amounts of natural antioxidants that consist of water- and lipid-soluble compounds. Hexane-insoluble and hexane-soluble fractions were separated from 100% methanolic extract from purple rice bran (RBE-HI and RBE-HS, respectively). Total anthocyanin, tannin, flavonoid, and phenolics contents were determined in those fractions, and their antioxidant capacities were evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capability, oxygen radical absorbance capacity (ORAC), and iron chelating capability (ICC). RBE-HI and RBE-HS were also added to restructured patties made from minced channel catfish (Ictalurus punctatus) belly flap meat. Lipid oxidation, color, and/or textural properties were determined for raw and cooked patties during a 12-d storage at 4 degrees C. All antioxidant indices, except for ICC, of RBE-HI were significantly higher than those of RBE-HS due probably to its higher anthocyanin content (P < 0.05). RBE-HS showed higher ICC (P < 0.05). However, both fractions showed similar antioxidant activity in raw and cooked patties during storage, resulting from the complexity of antioxidant action in food systems. Textural properties (hardness, cohesiveness, chewiness, and springiness) in cooked patties with RBE-HS and RBE-HI were well maintained during storage, but changed significantly in the control (P < 0.05). Only RBE-HS limited microbial growth in raw patties during storage (P < 0.05), but its inhibitory effect was marginal because of low-dose and physical interactions with the matrix. L* (lightness) and a* (redness) of raw and cooked patties decreased significantly by both fractions, whereas b* (yellowness) was significantly decreased by RBE-HI and increased by RBE-HS (P < 0.05). In conclusion, we suggest that purple rice bran extract is applicable to meat products as a natural preservative, but color change in the products may limit its application.

Lipid oxidation, color, and volatiles of double-packaged pork loins with various oleoresin or oleoresin–tocopherol combinations were determined to establish the best oleoresin–tocopherol conditions that can improve the quality of irradiated raw and cooked pork loins. Rosemary and α-tocopherol combination at 0.05% and 0.02% of meat weight, respectively, showed the most potent antioxidant effects in reducing both TBARS values and the amounts of volatile aldehydes in irradiated raw and cooked pork loins. The antioxidant combination, however, did not affect the production of sulfur volatiles responsible for irradiation off-odor and showed little effects on color changes in irradiated raw and cooked pork loins. Exposing double-packaged irradiated pork to aerobic conditions for 3 days during the 10-day storage was effective in controlling both lipid oxidation and irradiation off-odor, regardless of packaging sequences.

The structural isomers formed by the homogeneous rhodium-catalyzed isomerization of several vegetable oils have been elucidated. A detailed study of the isomerization of the model compound methyl linoleate has been performed to correlate the distribution of conjugated isomers, the reaction kinetics, and the mechanism of the reaction. It has been shown that [RhCl(C8H8)2]2 is a highly efficient and selective isomerization catalyst for the production of highly conjugated vegetable oils with a high conjugated linoleic acid (CLA) content, which is highly desirable in the food industry. The combined fraction of the two major CLA isomers [(9Z,11E)-CLA and (10E,12Z)-CLA] in the overall CLA mixture is in the range from 76.2% to 93.4%. The high efficiency and selectivity of this isomerization method along with the straightforward purification process render this approach highly promising for the preparation of conjugated oils and CLA. Proposed improvements in catalyst recovery and reusability will only make this method more appealing to the food, paint, coating, and polymer industries in the future.

Patties were prepared using the breast meat from 15-wk-old turkeys fed one of the 8 dietary treatments [Con, control; VE, 200 IU/kg vitamin E; Se, 0.3 mg/kg selenium; CLA, 2.5% conjugated linoleic acids; VE + Se, 200 IU/kg vitamin E + 0.3 mg/kg selenium; VE + CLA, 200 IU/kg vitamin E + 2.5% CLA; Se + CLA, 0.3 mg/kg selenium + 2.5% CLA; VE + Se + CLA, 200 IU/kg vitamin E + 0.3 mg/kg selenium + 2.5% CLA] for 4 wk. Patties were vacuum-packaged in oxygen-impermeable bags, and then irradiated with 0 or 1.5 kGy. Irradiated breast meats were cooked and vacuum-packaged or aerobically packaged, and the quality of meat was evaluated after 0 and 7 d of storage at 4 °C. Dietary VE + Se, VE + CLA, Se + CLA, and VE + Se + CLA treatments reduced lipid oxidation of cooked irradiated (1.5 kGy) turkey breast meat by 24%, 29%, 26%, and 40%, respectively, compared to that of the control after 7 d of storage under aerobic conditions. Dietary treatments had no influences on the color of nonirradiated cooked turkey breast. However, dietary VE and Se decreased the internal a* value of irradiated meats in vacuum packaging at days 0 and 7, and the effect was even greater when VE and Se were combined with CLA. Dietary VE, Se, and CLA combinations significantly reduced the production of volatiles, especially those related to lipid oxidation. Dietary VE + Se, VE + CLA, and VE + Se + CLA reduced the difference in sulfur-containing compounds between irradiated and nonirradiated meat. Aerobic packaging was more effective than vacuum packaging in reducing sulfur-containing compounds. Therefore, dietary VE, Se, and CLA combinations plus aerobic packaging were effective in reducing the odor problems induced by irradiation.

The objective of this study was to evaluate the effect of dietary functional ingredients vitamin E (VE), Se, and conjugated linoleic acid (CLA), alone or in combination, on the quality of irradiated turkey breast meat. A total of 480 male turkeys (11-wk-old, raised on a cornsoybean basal diet) were randomly allotted to 32 pens and fed 1 of 8 experimental diets (4 pens/treatment) supplemented with none (control), 200 IU/kg of VE (VE), 0.3 ppm Se (Se), 2.5% CLA (CLA), 200 IU/kg of VE + 0.3 ppm Se (VE + Se), 200 IU/kg of VE + 2.5% CLA (VE + CLA), 2.5% CLA + 0.3 ppm Se (CLA + Se), 200 IU/kg of VE + 0.3 ppm Se + 2.5% CLA (VE + Se + CLA) for 4 wk. At 15 wk of age, all birds were slaughtered, and breast muscles of 8 birds from each pen were separated, pooled, and ground. Patties were prepared using the ground meat, aerobically packaged, and irradiated at 0 or 1.5 kGy absorbed dose. Lipid oxidation, color, and volatiles of the patties were measured after 0, 7, and 12 d of storage at 4 degrees C. The content of VE and Se and fatty acid composition of lipids were also determined. Dietary supplementation of VE and CLA increased their concentrations in turkey breast. Dietary CLA decreased monounsaturated and non-CLA polyunsaturated fatty acids content in meat. Irradiation increased (P0.05) Hunter color redness value of turkey breast and accelerated lipid oxidation, regardless of dietary treatments. However, dietary VE, Se, and CLA, alone and in combinations, decreased (P0.05) lipid oxidation in meat caused by both irradiation and storage. It was concluded that dietary supplementation of VE, Se, and CLA, alone and in combination, improved the storage stability of irradiated turkey breast meat.

Irradiated restructured pork loins treated with rosemary–tocopherol/double-packaging had lower TBARS values than vacuum-packaged control after 10 days of refrigerated storage. The rosemary–tocopherol combination, however, had no effect on the production of sulfur volatiles responsible for the irradiation off-odor, and color changes in irradiated pork. V7/A3 double-packaging was effective in reducing the sulfur volatiles significantly. Rosemary–tocopherol combination was highly effective in reducing the volatile hexanal in irradiated restructure pork. Irradiation was effective in reducing Listeria monocytogenes and Salmonella typhimurium inoculated on the surface of restructured pork loin in dose-dependent manner. The irradiation D10 values for L. monocytogenes and S. typhimurium were 0.58 and 0.55 kGy, respectively. During the 20 days of refrigerated storage, L. monocytogenes in both nonirradiated and irradiated samples grew gradually, but the number of S. typhimurium decreased. The added rosemary–tocopherol, however, showed little bacteriocidal effects to L. monocytogenes and S. typhimurium. � 2006 Elsevier Ltd. All rights reserved.

Breast rolls with 6 antimicrobial additive treatments—no preservatives (control), 0.1% potassium benzoate (PB), 2% sodium lactate (SL), 0.1% potassium benzoate plus 2% sodium lactate (PB + SL), 2% sodium lactate plus 0.1% sodium diacetate (SL + SDA), and 0.1% potassum benzoate, 2% sodium lactate, and 0.1% sodium diacetate (PB + SL + SDA)—were prepared. Samples were irradiated at 0, 1.0, or 2.0 kGy, and then the quality characteristics of turkey rolls were analyzed. Adding 2% SL increased the hardness, springiness, cohesiveness, chewiness, and resilience of breast rolls. Addition of PB or SDA, and irradiation had no significant effect on texture. Adding 2% SL affected color values. The color a* and b* values of turkey rolls with 2% SL added were significantly lower than those of the control, and this difference was maintained after irradiation and during storage. No difference in color and texture was observed between turkey rolls added with SL and those added with SL + PB + SDA. Breast rolls containing antimicrobials had more lipid oxidation than control. Irradiation and storage slightly enhanced lipid oxidation, although the overall lipid oxidation was very low. Irradiation promoted the formation of dimethyl disulfide and dimethyl trisulfide. Adding PB in breast rolls greatly increased the formation of benzene during irradiation, whereas other antimicrobial additives had no significant effects on volatiles.

Beef loins, aged for different lengths of time post slaughter, were treated with ionizing radiation, irradiated ground beef produced volatile sulfur compounds (S-volatiles) responsible for the unique irradiation odor and accelerated lipid oxidation. The quality charges by irradiation became greater as aging and storage time increased. During aerobic storage, the S-volatiles disappeared whereas volatile aldehydes drastically increased in irradiated beef.Addition of ascorhic acid at 0.1% (wt/wt) or sesanol) α-locopherol at each 0.01% level to ground breef before irradiation effectively reduced lipid oxidation and S volatiles. As storage time increased, however, the antioxident effect of sesanol + tocopherol in irradiated ground beef was superior to that of ascorbic acid.

This study was aimed at determining the effect of irradiation of shell eggs on the physiochemical and functional properties of liquid egg white during storage. Color and textural parameters of irradiated liquid egg white after cooking were also determined. Shell eggs were irradiated at 0, 2.5, 5, or 10 kGy using a linear accelerator. Egg white was separated from yolk and stored in at 4°C up to 14 d. Viscosity, pH, turbidity, foaming properties, color, and volatile profile of liquid egg white, and color and texture properties of cooked egg white were determined at 0, 7, and 14 d of storage. Irradiation increased the turbidity but decreased viscosity of liquid egg white. Foaming capacity and foam stability were not affected by irradiation at lower dose (2.5 kGy), but were deteriorated at higher doses (≥5.0 kGy) of irradiation. Sulfur-containing volatiles were generated by irradiation and their amounts increased as the irradiation dose increased. However, the sulfur volatiles disappeared during storage under aerobic conditions. Lightness (L* value) and yellowness (b* value) decreased, but greenness (-a* value) increased in cooked egg white in irradiation dose-dependent manners. All textural parameters (hardness, adhesiveness, cohesiveness, chewiness, and resilience) of cooked egg white increased as the irradiation dose increased, but those changes were marginal. Our results indicated that irradiation of shell egg at lower doses (up to 2.5 kGy) had little negative impact on the physiochemical and functional properties of liquid egg white, but can improve the efficiency of egg processing due to its viscosity-lowering effect. Therefore, irradiation of shell eggs at the lower doses has high potential to be used by the egg processing industry to improve the safety of liquid egg without compromising its quality.

This study was conducted to determine the effects of dietary cholesterol (CHO) and cholesterol oxidation products (COPs) on the induction of pathological lesions in rabbit liver tissues. Liver lesions were induced only when the levels of CHO and COPs in the diet were very high. The amount of CHO measured in the liver increased when dietary CHO was increased; by comparison, dietary COPs affected liver CHO amounts to a lesser extent. The TBARS (thiobarbituric acid reactive substances) value measured for the liver samples also increased when dietary CHO and COP levels were elevated, and the TBARS value was more strongly affected by the amount of COPs in the diet than by the amount of CHO. At 6 and 12 weeks, COP levels were the highest in the group that received 1.2 g CHO + 0.8 g COPs, followed by the 0.5 g CHO + 0.5 g COPs and 1.6 g CHO + 0.4 g COPs groups; the control (0 g) group showed the lowest COP levels among all groups. In this study, we found that not only dietary CHO but also COPs were involved in hypercholesterolemia induced liver lesions when the amount of CHO and COPs was high.

Hydrocarbons, gas compounds, and off-odor volatiles were determined for irradiated (0 or 5 kGy) commercial sausages with different fat contents (16% and 29%) during a 60-d storage period at 4 ◦C. Total of 4 hydrocarbons (C14:1, C15:0, C16:2, and C17:1) were detected only in irradiated sausages: the amount of C16:2 was the highest, followed by C17:1, C14:1, and C15:0. The concentrations of hydrocarbons decreased significantly (P < 0.05) with storage, but were still detectable at the end of 60-d storage. Irradiated sausages produced significantly higher amounts of CO than the nonirradiated ones. CH4 was detected only in irradiated sausages. Dimethyl disulfide was detected only in irradiated sausages and its concentration decreased significantly (P < 0.05) with storage. Fat content of sausages showed a significant effect on the production and retention of hydrocarbons, gas compounds, and sulfur volatiles in irradiated sausages during storage. Some hydrocarbons (C16:2, C17:1, C14:1, and C15:0), CH4, and dimethyl disulfide were only found in irradiated sausages indicating that these compounds can be used as potential markers for irradiated sausages.

This study was aimed at determining the effect of irradiation of shell eggs on the physiochemical and functional properties of liquid egg white during storage. Color and textural parameters of irradiated liquid egg white after cooking were also determined. Shell eggs were irradiated at 0, 2.5, 5, or 10 kGy using a linear accelerator. Egg white was separated from yolk and stored in at 4°C up to 14 d. Viscosity, pH, turbidity, foaming properties, color, and volatile profile of liquid egg white, and color and texture properties of cooked egg white were determined at 0, 7, and 14 d of storage. Irradiation increased the turbidity but decreased viscosity of liquid egg white. Foaming capacity and foam stability were not affected by irradiation at lower dose (2.5 kGy), but were deteriorated at higher doses (≥5.0 kGy) of irradiation. Sulfur-containing volatiles were generated by irradiation and their amounts increased as the irradiation dose increased. However, the sulfur volatiles disappeared during storage under aerobic conditions. Lightness (L* value) and yellowness (b* value) decreased, but greenness (-a* value) increased in cooked egg white in irradiation dose-dependent manners. All textural parameters (hardness, adhesiveness, cohesiveness, chewiness, and resilience) of cooked egg white increased as the irradiation dose increased, but those changes were marginal. Our results indicated that irradiation of shell egg at lower doses (up to 2.5 kGy) had little negative impact on the physiochemical and functional properties of liquid egg white, but can improve the efficiency of egg processing due to its viscosity-lowering effect. Therefore, irradiation of shell eggs at the lower doses has high potential to be used by the egg processing industry to improve the safety of liquid egg without compromising its quality.

Hydrocarbons, gas compounds, and off-odor volatiles were determined for irradiated (0 or 5 kGy) commercial sausages with different fat contents (16% and 29%) during a 60-d storage period at 4 °C. Total of 4 hydrocarbons (C14:1, C15:0, C16:2, and C17:1) were detected only in irradiated sausages: the amount of C16:2 was the highest, followed by C17:1, C14:1, and C15:0. The concentrations of hydrocarbons decreased significantly (P < 0.05) with storage, but were still detectable at the end of 60-d storage. Irradiated sausages produced significantly higher amounts of CO than the nonirradiated ones. CH4 was detected only in irradiated sausages. Dimethyl disulfide was detected only in irradiated sausages and its concentration decreased significantly (P < 0.05) with storage. Fat content of sausages showed a significant effect on the production and retention of hydrocarbons, gas compounds, and sulfur volatiles in irradiated sausages during storage. Some hydrocarbons (C16:2, C17:1, C14:1, and C15:0), CH4, and dimethyl disulfide were only found in irradiated sausages indicating that these compounds can be used as potential markers for irradiated sausages.

Sensory and quality issues are among the most important factors that influence consumer purchasing decisions of meat products. This chapter discusses the most important sensory and quality issues, which include appearance, texture, flavor/taste, functional properties and nutritional values associated with a both packaged fresh and processed poultry product. The extent to which the mode of packaging is a factor is also addressed.

Rice bran, a byproduct of the rice milling process, contains most of the phytochemicals. This study aimed at determining the concentrations of lipophilic, solvent-extractable (free), and cell wall-bound (bound) phytochemicals and their antioxidant capacities from brans of white, light brown, brown, purple, and red colors, and broccoli and blueberry for comparison. The concentrations of lipophilic antioxidants of vitamin E (tocopherol and tocotrienols) and γ-oryzanols were 319.67 to 443.73 and 3861.93 to 5911.12 μg/g bran dry weight (DW), respectively, and were not associated with bran color. The total phenolic, total flavonoid, and antioxidant capacities of ORAC (oxygen radical absorbance capacity), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, and iron-chelating in the free fraction were correlated with the intensity of bran color, while variations of these in the bound fraction were less than those in the free fraction among brans. Compounds in the bound fraction had higher antioxidant capacity of ORAC than DPPH, relative to those in the free fraction. The bound fraction of light-color brans contributed as much to its total ORAC as the free fraction. Total proanthocyanidin concentration was the highest in red rice bran, while total anthocyanin was highest in purple brans. The predominant anthocyanin was cyanidin-3-glucoside. Red and purple brans had several fold higher total phenolics and flavonoids as well as ORAC and DPPH, from both free and bound fractions, than freeze-dried blueberry and broccoli. These results indicate that rice brans are natural sources of hydrophilic and lipophilic phytochemicals for use in quality control of various food systems as well as for nutraceutical and functional food application.

Chicken breast was more resistant to various exogenous oxidative factors than beef loin: addition of NaCl did not increase TBARS values and nonheme content of raw chicken breast, but significantly increased those of raw beef loin patties during storage. Addition of NaCl+Mb did not affect lipid oxidation in raw chicken breast patties, but decreased the TBARS of beef loin during storage. Addition of NaCl+Fe(III) or NaCl+Fe(II) increased the TBARS values of both raw chicken breast and beef loin during storage, but the increase was greater in beef loin than in chicken breast. The TBARS values of all cooked chicken breast and beef loin increased during 7-day storage, but the increases in cooked chicken patties were significantly smaller than those of cooked beef loin patties with the same treatments. Addition of NaCl and cooking caused severe degradation of myoglobin, leading to a significant increase in free ionic iron content in beef loin. It is suggested that free ionic iron is the major catalyst for lipid oxidation, and the high “storage-stable” ferric ionic reducing capacity and “heat-stable” ferric ion reducing capacity in chicken breast were responsible for the high oxidative stability for raw and cooked chicken breast compared with beef loin under prooxidants, cooking and storage conditions.

Chicken breast and beef loin were ground, and no, NaCl, NaCl+myoglobin, NaCl+Fe(II), or NaCl+Fe(III) additions were made; patties were then prepared. Half of the patties were packaged in oxygen-permeable bags and stored at 4 degrees C for 10 days, and the other half were cooked in a 95 degrees C water bath to an internal temperature of 75 degrees C, packaged in oxygen-permeable zipper bags, and stored at 4 degrees C for 7 days. The oxidative stability of raw and cooked chicken breast and beef loin were determined during storage. Chicken breast was more resistant to various exogenous oxidative factors than beef loin: addition of NaCl did not increase TBARS values and nonheme content of raw chicken breast, but significantly increased those of raw beef loin patties during storage. Addition of NaCl+Mb did not affect lipid oxidation in raw chicken breast patties, but decreased the TBARS of beef loin during storage. Addition of NaCl+Fe(III) or NaCl+Fe(II) increased the TBARS values of both raw chicken breast and beef loin during storage, but the increase was greater in beef loin than in chicken breast. The TBARS values of all cooked chicken breast and beef loin increased during 7 days of storage, but the increases in cooked chicken patties were significantly smaller than those of cooked beef loin patties with the same treatments. Addition of NaCl and cooking caused severe degradation of myoglobin, leading to a significant increase in free ionic iron content in beef loin. It is suggested that free ionic iron is the major catalyst for lipid oxidation, and the low "storage-stable and heat-stable" ferric ion reducing capacity in chicken breast were responsible for the high oxidative stability for raw and cooked chicken breast compared with beef loin under prooxidants, cooking, and storage conditions.

The susceptibility of meats from different animal species (chicken breast [CB] and thigh [CT], pork [PL and beef [BL]) to lipid oxidation was studied. The amounts of TBARS in raw PL, CB, and CT did not change during a 7-d storage period. TBARS values of raw BL, however, significantly increased during 7-d storage because of high heme iron content, high lipoxygenase-like activities, and low 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities. Ferric ion reducing capacities (FRC) were detected in all raw meats, but their characteristics were different: storage-unstable in CB and CT and storage-stable in PL and BL. Ferric ion reducing capacities in raw CB and CT was higher than those of PL and BL, and could be related to their high oxidative stability. The TBARS values of cooked meat increased significantly with storage. The rates of TBARS increase in cooked CT and BL were significantly higher than those of cooked CB and PL after a 7-d storage. Nonheme iron content in cooked BL was higher than other meats and increased significantly after 7 d. Cooked BL had a higher amount of heat-stable FRC, which acted as a prooxidant in the presence of high free ionic irons, than other meats. Therefore, high heat-stable FRC and increased nonheme iron content in cooked BL were responsible for its high susceptibility to lipid oxidation. Despite relatively low nonheme iron and heat-stable FRC levels, cooked CT showed similar levels of TBARS to cooked BL after a 7-d storage because of its high PUFA content.

This study was aimed at developing value-added low sodium chloride (NaCl), phosphate-free restructured patties using minced channel catfish (Ictalurus punctatus) belly flap meat. The effect of microbial transglutaminase (MTGase) and nonmeat proteins (isolated soy protein, ISP, and whey protein concentrate, WPC; 1.7%, respectively) alone and in combination were evaluated to improve cooking yield and textural properties in patties with reduced NaCl and no phosphate. The concentration effect of MTGase (0.05% to 0.7%) was also studied. The addition of MTGase increased textural properties such as binding strength, hardness, cohesiveness, chewiness, and springiness, but decreased cooking yield of the patties (P < 0.05). Isolated soy protein increased cooking yield (P < 0.05), but did not affect textural properties. Inclusion of WPC did not increase cooking yield or impact textural properties of patties. The combination of MTGase and ISP significantly increased both the cooking yield and textural properties of patties. As the concentration of MTGase increased at constant ISP, the textural properties of cooked patties significantly increased, but cooking yield decreased (P < 0.05). In conclusion, we suggest that the combination of 0.05% to 0.1% of MTGase with 1.7% ISP is optimal for development of a low NaCl, phosphate-free patty using minced catfish belly flap meat.

Raw and cooked breast patties from turkeys fed 8 different diets [control; 200 IU/kg of vitamin E (VE); 0.3 mg/kg of Se; 2.5% conjugated linoleic acids (CLA); 200 IU/kg of VE + 0.3 mg/kg of Se; 200 IU/kg of VE + 2.5% CLA; 0.3 mg/kg of Se + 2.5% CLA; and 200 IU/kg of VE + 0.3 mg/kg of Se + 2.5% CLA] were treated with 2 irradiation doses (0 and 1.5 kGy) and 2 packaging methods (vacuum and aerobic). Raw and cooked samples from 32 treatments were tested by 8 trained sensory panelists for turkey aroma and irradiation off-aroma. Based on the sensory scores, the 3 dietary treatments producing the most and the least off-aroma were selected and used for a consumer acceptance study. Sensory results of raw meat showed that turkey aroma was intense in aerobically packaged meat, whereas irradiation off-aroma was intense with vacuum packaging. Raw meats from dietary treatments containing CLA (CLA, VE + CLA, Se + CLA, VE + Se + CLA) had greater turkey aroma scores, whereas those containing VE (VE and VE + Se) had lower scores than the control. Dietary treatments containing VE (VE, VE + Se, VE + Se + CLA) significantly lowered (P < 0.05) irradiation off-aroma in raw turkey breast meat, whereas CLA increased it, especially when the meats were packaged aerobically. In cooked meat, however, irradiation and packaging had no effect on turkey meat aroma and irradiation off-aroma. Cooked meat from turkeys supplemented with VE (VE and VE + Se) had less (P < 0.05) irradiation off-odor than other dietary treatments. Dietary CLA increased the irradiation off-aroma in cooked meat, which could not be reduced, even when VE and Se were combined in the diet. Irradiation off-aroma of raw meat was not pleasant for most consumers, and dietary supplementation of VE and VE + Se improved consumer acceptance of irradiated raw meat. For cooked meat samples, consumers preferred both color and flavor of irradiated meat to nonirradiated meat.

When dietary TA was increased from 0 to 200 IU/kg diet, plasma and muscle vitamin E levels increased by 5- and 4-fold, respectively. Dietary TA at 100 IU/kg diet significantly improved the storage stability of turkey breast, and it was more distinct in irradiated than nonirradiated meats. Both irradiation and dietary TA increased a*-values of turkey breast meat, but irradiation had a stronger impact. The redness of meat decreased during the 7-d storage, but irradiated meat maintained redder color than nonirradiated. Irradiated meat produced more sulfur volatiles and aldehydes than nonirradiated meats, and dietary TA effectively reduced these compounds during storage. The effects of dietary TA on the reduction of off-odor volatiles were more distinct in previously frozen-stored meats than in fresh meats.